SCIENCE. 



[Vol. XII. No. 291 



PROCEEDINGS OF THE AMERICAN ASSOCIATION. 



The work accomplished in the various sections of the American 

 Association for the Advancement of Science is very satisfactory if 

 considered as a whole. The number of members attending the 

 meeting was comparatively small ; while many leading scientists 

 took part in the discussions, and brought important problems be- 

 fore the sections, thus inducing many of the most able students to 

 <;o-operate in their solution. 



Section B (Physics) did very good work in discussing fully the re- 

 "port of the committee on the teaching of physics. Section A (Mathe- 

 matics) joined on the first day in these discussions, and did not hold 

 any meeting in its own hall. The report of the committee was 

 made by Prof. T. C. Mendenhall. In substance it is as follows : — 



The publication in the English language within a few years, of 

 several e.xcellent text-books of physics and a few laboratory guides 

 of a high order of merit, together with a considerable advance in 

 real scholarship among teachers, makes it possible to use the 

 phrases ' text-book work,' ' lecture-work," and ' laboratory practice,' 

 with a fair chance of being understood ; yet it may be well to re- 

 mark, that, where the latter is referred to, something very different 

 from mere illustrative experimentation is meant ; it being the opin- 

 ion of the committee that the work in the laboratory should be 

 quantitative rather than qualitative, and always of as high a degree 

 of precision as is possible with the appliances available. 



In order to give definiteness to its conclusions, the committee 

 undertook to answer the following questions : — 



I. In what grade of the public school should physics-teaching 

 begin ? 3. What should be the character of this first instruction, 



oral, by text-book, by laboratory methods, etc. ? 3. What should 



be the character of the physics-teaching in the high school, — text- 

 book, laboratory, text-book followed by laboratory, laboratory fol- 

 lowed by text-book, or laboratory and text-book combined ? 4. 

 What knowledge of physics should be required for admission 

 to coUeo-e ? 5. What should be the minimum course in physics 

 for undergraduate students, and what should be the nature of this 

 course.-" 



The answers are as follows : — 



1. In answer to the first question, it is the opinion of the com- 

 mittee that instructions in physics may begin, with profit, in what 

 is generally known as the ' grammar school.' At the same time it 

 is decidedly opposed to any general recommendation that it must 

 begin there or in the primary school. Here, perhaps more than 

 anywhere else, nearly every thing depends upon the teacher. 

 One who has a strong liking for and a good knowledge of physics 

 will be tolerably certain to succeed, while another not thus equipped 

 for the work is equally certain to fail. 



2. When taught in the grammar school and by a competent 

 teacher, it should be done mainly by and through illustrative ex- 

 periments. These may be of the simplest character, involving and 

 exhibiting some of the fundamental principles of science ; and they 

 should generally be made by the teacher, the pupils being encour- 

 aged to repeat, to vary, and to extend. 



3. In any discussion of the character of instruction in physics in 

 the high school, one fact of the utmost importance must not be 

 lost sight of. It is that a large majority of the young people who 

 are educated in the pubUc schools receive their final scholastic 

 training in the high school. Its course of study must be in harmony 

 with this fact, such provision as may be made for those who con- 

 tinue their studies in college or university being merely incidental. 

 It is important that the student should be made acquainted, if only 

 to a limited extent, with the methods of physical investigation, and 

 that he should be able himself to plan and carry out an attack up- 

 on some of the simpler problems of the science. It is believed that 

 the two very desirable ends can be reached without giving an un- 

 due share of the time and energy of the pupil to the subject. As- 

 suming the high-school course to consist of four years of three 

 terms each, it is recommended that the study of physics should be- 

 gin not earlier than the third year ; that it should continue through 

 one year, three hours a week being devoted to it, not including the 

 time necessary for the preparation of the lesson ; and that during 

 the first two terms the work should be text-book work, accom- 

 panied by illustrative experiments performed by the instructor, and 



made as complete as his facilities will allow, while the last term 

 should be devoted to simple laboratory exercises. 



4. As to the requirements in physics for admission to college, it 

 is sufficient to say that the course indicated above should be re- 

 quired for admission to any and all courses in the college. 



5. In reference to the minimum course in physics for under- 

 graduate students in the college, it seems important to avoid the 

 mistake of asking too much. In many institutions, and especially 

 where the elective system largely prevails, it is possible at present for 

 students to receive a degree and yet be almost absolutely ignorant 

 of the principles of physics. It is the judgment of the committee 

 that a knowledge of this subject constitutes one of the necessary 

 and essential elements of a liberal education, and a minimum 

 course of three hours per week for one year is recommended. 

 What is usually known as the junior year is most desirable for this 

 work, as at that time the student is sufficiently mature and has 

 acquired the necessary training in mathematics to enable him to 

 make the best of what he does. It is recommended that this course 

 consist entirely of text-book and recitation work, with lectures fully 

 and completely illustrated on the professor's table. 



The report is signed by T. C. Mendenhall, William A. Anthony, 

 H. S. Corbait, and F. H. Smith. 



The very large attendance of members at the session when the 

 report was read, and the continued discussions, show that the im- 

 portance of the question at issue is well appreciated. The last 

 day of the meeting was exclusively devoted to this subject. The 

 report was very favorably received and unanimously indorsed. It 

 was the opinion of the section that there should be a wide distri- 

 bution of the report in the educational journals of the country. 



The Physical Section did a considerable amount of valuable 

 work besides that of the committee. On the first day W. LeConte 

 Stevens read a very interesting paper on ' The Quality of Musical 

 Sounds.' It contained a sketch giving the method adopted by 

 Helmholtz in his investigation on musical quality, which resulted 

 in the conclusion that " differences in musical quality of tone de- 

 pend solely on the presence and strength of partial tones, and in no 

 respect on the differences of phase under which these partial tones 

 enter into composition." 



In a paper on the 'Beats of Imperfect Harmonies,' read in 1878 

 before the Royal Society of Edinburgh, Sir William Thomson ex- 

 pressed conclusions inconsistent with those previously reached by 

 Helmholtz, and the question was subsequently studied by means of 

 the wave siren, invented by Rudolph Koenig of Paris, for the pur- 

 pose of testing the effect of change of phase in quality of tone. 

 This instrument was brought to America a few years ago, but was 

 injured in transit so that it could not be operated. It has since 

 been further improved. Mr. Stevens has had an opportunity to 

 test its action in company with M. Koenig, and believes that 

 through' the instrument the truth has been established that varia- 

 tion in phase among the components of a composed sound is a dis- 

 tinct element in determining musical quality. 



Dr. E. P. Howland described the most recent methods of instan- 

 taneous photography, and during his lecture showed a very inter- 

 esting specimen of such work, — the photograph of a mule whose 

 head had just been blown off with dynamite. It was taken before 

 the animal fell. The paper was illustrated by e.xperiments and 

 projections. 



E. L. Nichols and W. S. Franklin reported on some of their 

 recent experiments on the direction and velocity of the electric 

 current. A coil of wire of 390 turns was driven at a very 

 high rate of speed, the axis of the coil being the axis of rota- 

 tion. When the coil reached 338 revolutions per second, the linear 

 velocity of the wire in the direction of its own length amounted to 

 8,000 centimetres per second. By means of two brush contacts at 

 the axis, a current was sent through the coil while the latter was in 

 motion. The magnetic moment of the coil was determined by 

 means of a very sensitive astatic pair of magnets carrying a mirror. 



Readings were taken with the coil at rest and in revolution, the 

 motion of the coil and the direction of the current being repeatedly 

 reversed. If the electric current result from the flow of a fluid 

 through the wire, in other words, if it may be considered as pos- 

 sessing direction and finite velocity, the influence of a motion of the 

 conductor with or against the current should produce an appre- 



